Living the American Dream

While most of the world's richest people earned their money, some had farther to climb. Neither Bill Gates nor Warren Buffett inherited wealth, but they were raised in affluent homes so they didn't have to worry about keeping their families fed. In contrast, there's something reassuring about a billionaire who grew up poor—something that goes beyond the classic, clichéd tale of the American Dream. For all the allure that stems from the lifestyle afforded by such wealth, the billionaires on this list say their mission was rarely about the grand money game. Making a billion dollars from nothing was most often about filling a need and getting started in a small business. Whether they were born in poverty, dropped out of high school, immigrated to the U.S., or even lived homeless for a time, these 20 Americans started at the bottom and worked their way to the top.